1. Field of the Invention
The present invention relates generally to controlling the flow of liquid in liquid treatment equipment, and more particularly to providing a solely-bent baffle, having no shape-holding facilities other than bends that form structural channels or beams, for controlling the flow of the liquid in equipment for processing liquid, and to methods of providing an unbent baffle blank, and to methods for bending an unbent baffle blank to provide the solely-bent baffle.
2. Description of the Related Art
Liquid flows into liquid treatment equipment in which the liquid is subjected to various processing operations. The processing operations may be of the contact-type or of a physical-type, for example. The contact-type may include, for example, processes in which the liquid is contacted with a chemical (e.g., for chlorinization or flocculation), or in which the liquid is mixed by energy imparted to the liquid, or in which the liquid is aerated by one or more gasses introduced to the liquid. In each contact process situation, a container 100, such as a three-dimensional container shown in FIGS. 1A and 1B, is provided to receive liquid (see arrows 102) to be processed and to provide a volume in which the contact processing may take place. Chemicals such as chlorine (see arrows 104) may, for example, be supplied to the container 100 from a pipe or other inlet 106. For proper processing, in many cases it is necessary to control the flow of the liquid 102 within the three-dimensional container 100. Such control may be of the direction of the liquid 102, as by using flow controllers, also known as baffles, 110, for example, which may extend between opposed walls 112 of the container 100. The direction of liquid flow may be from an inlet 114 downwardly under a first of the baffles 110-1 (FIG. 1B) and upwardly over a second of the baffles 110-2. Alternatively, FIGS. 2A and 2B show that for processing, baffles 110-3 and 110-4 may extend partially between the walls 112 so as to leave spaces 116 so that the liquid flow is toward one wall 112-1 and then toward the other wall 112-2. For mixing of the liquid 102, FIGS. 2A and 2B show a mechanical mixer 118 between the baffles 110-3 and 110-4. In another variation, the flow rate of the liquid 102 may be controlled as shown in FIGS. 3A and 3B by vertical baffles 110-5 and 110-6 having spaced openings 120, and for example, an aerator 122 may provide gas 124 that contacts the liquid 102. In each illustrated use of the baffles 110, a forward force (see arrows FF) may be applied by the liquid 102 against the baffle 110. The direction of liquid flow may also be reversed. In this case, the flow of liquid 102 that normally exits an outlet 122 may flow (see arrows 124) into the container 100 via the outlet 122 and apply a reverse force (see arrows FR) to the flow controller 110.
An example of such physical-type of liquid treatment equipment is a clarifier 130 shown in FIGS. 4A and 4B for removing materials 132 (FIG. 4B) from the liquid 102. These materials 132 are generally in the form of particles suspended in the liquid 102. The particles can be removed from the liquid 102 under the force of gravity when the flow of the liquid 102 is substantially reduced, as in a very low flow rate zone 134 in the clarifier 130. Since these materials 132 are generally solid and are said to xe2x80x9csettlexe2x80x9d out of the liquid 102, they are referred to as xe2x80x9csettleable solidsxe2x80x9d. Such settleable solids 132 may include naturally occurring materials (e.g., clay, silt, sand and dirt), chemical precipitants and biological solids. The word xe2x80x9csolidsxe2x80x9d as used herein to describe the present invention refers to such settleable solids 132. Also, since the settleable solids 132 xe2x80x9csettlexe2x80x9d out of the liquid 102, the clarifiers 130 are often referred to as xe2x80x9csettlersxe2x80x9d.
Clarifiers 130 are used, for example, to treat liquid 102 in water and waste water treatment plants. In water treatment, the water 102 drawn from a water supply has various non-settleable colloidal solids therein. When mixed with the chemicals 104 (FIG. 4A) in the contact-type of processing, the colloidal solids and chemicals agglomerate to form solids 132. In waste water treatment, the solids include organic solids, among other wastes. Water and waste water may be the liquids 102 treated in the clarifiers 130 to remove such solids 132, thereby making the water clear and suitable for use, reuse, or for further treatment, such as tertiary treatment. The word xe2x80x9cliquidxe2x80x9d as used herein to describe the present invention refers to water and waste water 102, and to other liquids which may be subjected to the contact-type processes described above. Because of the nature of such use or reuse, during treatment such liquids 102 must not receive any chemicals or other materials that are toxic to humans, for example.
Continuing to refer to the exemplary clarifiers 130, the very low flow rate zones 134 promote maximum settlement of the settleable solids 132 to a bottom 136 of the clarifiers 130. Clarifiers 130 typically include containers 100 (FIG. 4A) that are typically referred to as detention basins where the settlement of the solids 132 occurs. For convenience, the term xe2x80x9cbasinxe2x80x9d as used herein includes such three-dimensional containers 100 and such detention basins 100, and any similar containers (e.g., circular in shape) in which such contact-type or physical-type processing is performed.
Tubes or flat plates 138 mounted at fixed or variable angles relative to the surface of the liquid 102 have been used to form multiple ones of the very low flow rate zones 134 in the detention basins 100. The liquid 102 containing the settleable solids 132 flows into the detention basin 100 and must be directed to the bottom 136 of the basin 100 for flow upwardly in the flow zones 134 at flow rates that generally are slow enough to allow sufficient time for most of the settleable solids 132 to settle out of the liquid 102. As a result, most of the settleable solids 132 will have settled onto the plates or tubes 138 by the time the liquid 102 has flowed to tops 142 of the plates or tubes 138.
In the past, for both the contact-type and the physical-type of processing, liquid 102 flowing into such detention basin 100 for treatment has generally been controlled by providing one of two types of the flow controllers 110 across the opposite, vertically-extending walls 112 of the basin 100. Such incoming liquid 102 generally moves through the inlet 114 of the basin 100, and from the inlet 114 in a forward direction (see arrow 146 in FIG. 4B), generally parallel to the opposite, vertical walls 112. The prior flow controllers 110 extend across the opposed, vertical sides 112 and generally have a height H (FIG. 4B) less than the depth D of the liquid 102 in the basin 100, such that there is a space, or opening, 148 between the bottom 150 of the prior flow controllers 110 and the bottom 136 of the basin 100. The prior flow controllers 110 block the forward flow 146 of the liquid 102 that is above the bottom 150 of the flow controllers 110. However, the opening 148 allows the incoming liquid 102 to flow under the flow controllers 110 and into entrances 152 of the low flow zones 134, the entrances 152 being provided near the bottom 136 of the basin 100.
One type of such prior flow controller 110 is a slab of reinforced concrete generally formed in one piece extending across the opposed walls 112 and providing the opening 148 above the bottom 136 of the basin 100 for forward liquid flow to the entrances 152. The slab is formed by pouring the concrete in place in the basin 100. Over time, the concrete slab of the prior flow controller 110 deteriorates under the action of the incoming liquid 102 and the materials 132 carried by the incoming liquid 102, and must be removed and replaced. Since the concrete slab of the prior flow controller 110 may, for example, be as wide as ten feet, as high as twenty feet, and as thick as eighteen inches, the concrete slab of the prior flow controller 110 is very heavy. As a result, removal of the concrete slab of the prior flow controller 110 both requires use of costly equipment that is time-consuming to use, and increases the risk of injury to the staff that provides maintenance services for the basin 100.
Referring to FIGS. 5A and 5B, in an attempt eliminate the need for such costly equipment, for example, the concrete slabs of the prior flow controllers 110 have been replaced using boards 160 made of redwood. It has been typical for each opposite wall 112 to be provided with a vertically-extending bracket 162, and for the individual redwood boards 160 to be bolted to the brackets 162. Although the redwood boards 160 are easier to install than the concrete slabs, to minimize twisting the boards 160 have typically been made from so-called xe2x80x9cclear, all-heartxe2x80x9d lumber that is both rare and costly. Further, such redwood boards 160 also require maintenance that involves removal of the boards 160. For example, in use the boards 160 become saturated with the liquid 102 in which the boards 160 are constantly immersed, causing difficulties when attempts are made to remove the boards 160. Each liquid-saturated redwood board 160 is heavy and difficult to lift without use of a mechanical hoist. In an attempt to reduce costs, some have used lesser grades of redwood (other than the xe2x80x9cclear, all-heartxe2x80x9d grade) to make the boards 160. However, to overcome the decreased quality of the lesser grades, some have improperly treated the lesser-grade redwood boards 160 with arsenic, for example, which is highly toxic and therefore prohibited by applicable regulations for use in liquid 102 intended for human consumption.
FIG. 6 shows how the flow controllers 110 have in the past been provided in the containers 100 when the walls 112 are relatively widely spaced apart, as by twenty feet for example. In this case, separate sections 110S of the flow controller 110 may be provided. For each section 110S, the brackets 162 described with respect to FIG. 5A may be attached to the walls 112, or as shown, a concrete pier 164 may be installed vertically next to the wall 112, and the bracket 162 secured to the pier 164. To allow the boards 160 to be used in standard ten foot lengths for one section 110S, a central pier 166 has been secured by bolts to the bottom 136 (FIG. 4B) of the basin 100 between the walls 112. The pier 166 extends upwardly to provide support in the center of the basin 100. The central piers 166 have been made from stainless steel, for example, and may be secured to brackets 162 in the form of U-shaped slots which receive opposite ends of the boards 160. The boards 160 thus extend horizontally between the brackets 162 and are supported by the central pier 166 against the respective forward and reverse forces FF and FR of the flowing liquid 102. Although the boards 160 may thus be used across such widely spaced walls 112, the boards 160 are still subject to the above-described maintenance problems.
Therefore, what is needed is a way of providing an improved flow controller, or baffle, for use in liquid treatment equipment. In particular, what is needed is a baffle having a long useful life when constantly immersed in liquid to be treated, which life is long relative to that of the reinforced concrete flow controllers and the flow controllers made from clear, all-heart grade redwood. Also, what is needed is an improved flow controller that is more easily and safely removable from the equipment than the reinforced concrete flow controllers and the flow controllers made from clear, all-heart grade redwood. Further, what is needed is a method of fabricating an improved flow controller having all such benefits lacking in the prior reinforced concrete flow controllers and the prior flow controllers made from clear, all-heart grade redwood.
Broadly speaking, the present invention fills these needs by providing a flow controller, referred to below as a xe2x80x9cbafflexe2x80x9d, having no shape-holding facilities other than bends that define and hold the shape, or configuration, of structural channels, wherein the baffle may control the flow of the liquid in any of the above-described liquid treatment equipment, e.g., for the contact-type or the physical-type of processes. The present invention also fills these needs through methods of providing an unbent blank for making such baffle, and by providing operations for bending such unbent blank to provide such baffle. In particular, the present invention fills these needs by providing a preferably stainless steel unbent baffle blank that may be deformed by bending into a configuration that defines a plurality of structural channels of a baffle, wherein the deformed blank need not be held bent in such configuration by any fastener or welding, for example, and wherein the plurality of structural channels render the baffle able to withstand the various respective forces FF and FR, for example, applied to the baffle by the respective incoming liquid and by liquid having a reverse flow direction in the basin. Importantly, without use of such welding or such fasteners, the deformed baffle remains in the desired bent configuration notwithstanding such forces FF and FR applied to the baffle during the flow control operation of the baffle. Such bent baffle (that is not welded or fastened or otherwise secured in the desired configuration) is thus referred to as a xe2x80x9csoley-bentxe2x80x9d baffle to indicate, or describe, the structural characteristic of only being bent into a configuration implementing the desired plurality of structural channels, and to indicate, or describe, the structural characteristic of staying in such bent configuration without being retained in such configuration by welds or fasteners, or by any other structure added to the bent material from which the blank baffle is made. As a result, the solely-bent baffle does not have any corrosion sites that are typically found adjacent to locations at which welds are made. Such corrosion sites are characterized by chemical deterioration (even in stainless steel) and tend to isolate or focus stress, and over time are sites of deterioration of the baffle. Also, the solely-bent baffle does not have any holes to allow a fastener to extend through the baffle, such that there is no weakening of the solely-bent baffle by such holes and no tendency of normal operational vibrations to cause a fastener to become loose. The absence of such welds and holes and fasteners increases the potential period of time during which the soley-bent baffle may remain in service without maintenance (e.g., removal and replacement). Additionally, because the solely-bent baffle does not absorb the liquid and thus does remain in an original relatively light-weight condition (as compared to concrete or liquid-saturated redwood), any required maintenance may be easier and safer to perform using maintenance staff rather than costly hoists or other lifting equipment.
Other aspects and advantages of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the present invention.